Outcomes Following Penetrating Brain Injuries in Military Settings: A Systematic Review and Meta-Analysis

Abstract

While neurosurgeons are experienced in treating penetrating brain injuries (PBIs) in civilian settings, much less is known about management and outcomes of PBIs in military settings. A systematic review was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Data extracted included surgical management, age, gender, location/type of injury, initial Glasgow Coma Scale (GCS) score, and outcomes. The primary outcomes were last reported Glasgow Outcome Score (GOS) and mortality. The secondary outcomes included central nervous system infections, seizures, and cerebrospinal fluid leak/fistula. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used for outcome analysis. Twelve studies with 1738 patients treated for PBIs in military settings were included. The weighted mean age was 27.8 years, 86.7% were male, and 64.3% underwent neurosurgical intervention. Most patients (64.3%) presented with a GCS score >8, while 31.0% presented in a coma (GCS score <8). Over a median last follow-up time of 9 months, 68.6% achieved a favorable (GOS= 4-5) outcome and 34.2% achieved a poor (GCS score= 1-3) outcome. The overall mortality was 18.0%. A meta-analysis was performed using 5 of 12 studies to evaluate the effect of the presenting GCS score on primary outcomes. Patients with an initial GCS score <8 had statistically significant lower odds of a favorable (GOS= 4-5) outcome (OR: 0.03; 95% CI: 0.00-0.19; P: 0.000) and higher odds of mortality (OR: 28.46; 95% CI: 8.62-94; P: 0.000) than patients with an initial GCS score >8. The pooled rates of central nervous system infection, seizures, and cerebrospinal fluid leak/fistula were 13.8%, 13.2%, and 5.4%, respectively. In this first systematic review and meta-analysis of outcomes following combat-related PBIs, a GCS score >8 at presentation was found to be an important predictor of a favorable GOS and decreased mortality.